314 Ë 8 New progress of HTS Maglev vehicle
Tab. 8.11:Main parameters of the HTS Maglev vehicle.
PMG distance 8 m diameter
Levitation height 12–15 mm
Load capability 75–50 kg
Propulsion mode Airscrew propulsion
Max. acceleration 1 m/s^2
Running speed Maximum 15 km/h
PMG. Consequently, this asymmetric PMG design can help to realize the “straight line
to curve to straight line” running environment for HTS Maglev vehicle application.
8.5 New developments in HTS Maglev vehicle system
8.5.1An 8-m-diameter PM guideway test line
In the practical application, the homogeneity of an infinite PMG paved along its
route is a key problem. A homogeneous magnetic field distribution along the PMG’s
extended direction determines the fundamental frictionless operation of HTS Maglev
vehicles. Otherwise, there will be some magnetic drag forces produced during running
at any speed. This disturbance phenomenon is not expected and will violate the freely
stable levitation advantage of a HTS Maglev vehicle. Hence, before using any PMGs,
the homogeneity should be checked carefully in advance. Thus, in 2007, under the
support of the National 863 Plan, an 8-m-diameter PMG test line for the HTS Maglev
vehicle system was built to validate the assembly feasibility and accuracy of a long-
distance PMG. Table 8.11 gives the main parameters of this HTS Maglev vehicle system
based on Fig. 8.55.
As shown in Fig. 8.55, the levitation load was measured from 600 to 1034 N since
the 10–15-mm WH range is the most important. It is obvious that the practical FCH
should be higher than 30 mm; otherwise, the design levitation load target cannot be
obtained. It should be noted that the highest central magnetic field density of the PMG
was 1.557 T (see Fig. 8.56) by the optimization [55] and careful consideration of the
ferromagnetic material as a highly efficient flux collector during the PMG design.
From the viewpoint of the construction procedure for this HTS Maglev vehic-
le system, Fig. 8.57 shows the schematic drawing of the 8-m-diameter PMG test
line and the inset is a photo of two jointed PMG unit segments. The PMG test line
was composed of 240 PMG segments whose corresponding central angle was 3°.
Among those 240 PMG segments, the production pass percentage was 95.8%. It was
necessary that careful attention be paid to the homogeneity of the infinite PMG for
HTS Maglev vehicle application.